Hydraulic riveting machine



(No Model.) A Y R. E. TWEDDELL, J. PLATT &KJ IIELDING.

.-DIREGT ACTING HYDRAULIC RIVETING MACHINE.

No. 307' 355. Patented 0011.2 84.

UNTTED STATES- i Erice.,

l'ATENT RALPH HART TvvEDDELL, OE WESTMTNSTER, COUNTY OE MIDDLESEX, AND JAMES rLATT AND JOHN EIELDTNC, or GLOUCESTER, COUNTY OE GLOUCESTER, ENGLAND.

DIRECT-ACTING HYDRAULIC `RIVvETING-IVIACHIN'E.

SPECIFICATION forming part of 'l'.ietteraPatent4 No. 307,355, dated October 28, 1884.

Application filed April 19, 1884. (No model.) Patented in England February 3, 1883, No. 597; in France August G, 1883, No. 156,893, andin Belgium August G, 1883, No. 62,233.

To all whom it may concern,.-

Be it known that we, RALPH HART TWED- DELL, of Westminster, in the county of MiddleseX, and JAMES PLATT and JOHN FIELD- ING, of Gloucester, in the county of Gloucester, and country of England, have invented certain new and useful Improvements in Direct-Acting Hyd raulie Machines for Riveting, 81e.; and We do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others Skilled in the art to which it appertains to make and use the same.

Our invention relates to an improvement in direct-acting hydraulic machines for riveting, punching, &c., and more particularly to machines provided with additional plungers for closing together the plates to be riveted, the object of the same being to utilize the area of the additional plunger for giving additional force to the riveting-tool as it is completing its stroke; and it consists in the parts and combinations of parts, as will be more fully described, and pointed out in the claims.

In the accompanying drawings, Figure l is a view in longitudinal section of a machine embodying our invention. Fig. 2 is an end view ofthe same, and Fig. 3 represents a modification.

A represents the frame of the machine, the upper surface of which is adapted to receiveh the cylinders and plungers, to be hereinafter described. On this frame we secure the piston P, having Such area that the available pressure acting on it will give the maximum force required. This piston is recessed, and is provided with a supply opening, through Which the acting iiuid enters, and is tted Within cylinder Q of the plunger Q, which may be termed the riveting-plunger,77 and which carries at its outer end the riveting-tool q. This plunger is bored centrally to receive the plunger R, considerably less in area than the Xed piston P. The plunger R projects upwardly at its outer end, and is provided with an opening through which the riveting-tool passes. The smaller plunger, R, working in the bore R', which may be termed the closing-cylinder,77 carries at its end the closingtool r, which is in the form of a fork, having a limb on each side of the riveting-tool g, as shown in Fig. 2. At one sideof the smaller plunger, R, there is a still smaller plunger, S, for effecting the back-stroke of the plungers Qand R, working in a stationary cylinder, T, which may be termed the push-back cylinder. The hydraulic connections to these three cylinders are thus arranged: The small push-back cylinder T is always'in communication with the pressure reservoir or accumulator, so that the pressure on its plunger can push back the riveting-plunger Q and the closing-plunger R when the former is relieved from the hydraulic pressure. The rivetingplunger Q is in communication by pipe d with avalve of ordinary construction located at U, by which it can be made to communicate either with the pressure or with the free discharge. The closing-cylinder It can also be made to communicate with the pressure-reservoir or the discharge, or its outlet can be entirely closed. The plunger S is provided with a central bore, in which one end of the pipe a is fitted, and on which pipe the plunger moves. The opposite end of the plunger S is rigidly secured to the plunger R by the pipe b, thereby -forming a communication between the pipes c and the cylinder R.

In riveting with this machine the pressure is in the rst place allowed to act on both the riveting and closing plungers Q and R, the closing-tool r presses the plates together, and the riveting-tool q upsets the rivet with the force due to the excess of area of the rivetingcylinder Q' over that of the closing.- cylinder R. On now opening the discharge from the closing-cylinder R', the riveting-cylinder is relieved from the back-pressure due tothe area of R', and consequently the force applied tothe riveting-tool q is that due to the full area of the riveting-cylinder Q. The riveting being completed, the riveting-cylinder Q is opened to discharge by means of the'valve at U, and thereupdn the push-back plungerS effects the back-stroke of both the riveting and closing tools q and r. Vhcn onlya moderate riveting force is required and closing is unnecessary, the riveting tool q may be fixed, instead of the closing-tool r, on the plunger R, which latter can effect the riveting, the large riveting-cylinder Q remaining stationary.

From the foregoing it will be seen that by using two plungers-one for pressing the plates together and the other for riveting-the closing or pressing plunger will cease moving first, and the riveting-plunger, continuing to advance, causes a discharge of fluid through the pressure due to the whole area.

In order to economize the high -pressure liquid employed, we may make the rivetingcylinder communicate by a passage, p, governed by a check-valve, p,with the dischargecistern, and connect the closing-plunger R to the riveting-plunger Q by a shoulder, R, on the riveting-tool holder, as shown in Fig. 3. At first we admit the fluid under pressure only to the closing-cylinder R', and its plunger, advancing to effect a closing of the plates, draws with it the riveting-plunger Q, which becomes filled with low-pressure liquid. XVe then admit liquid under high pressure to the riveting-cylinder, thus effecting the riveting, as above described.

Ve do not claim, broadly, in this application a push-back plunger for forcing the riveting-plunger back into position, nor do we claim, broadly, a plunger having a cylinder formed in one end thereof in'which astationary piston fits, as these features are shown, described, and claimed in our pending applications, numbered 128,544 and 131,466.

Ve are aware that it is not broadly new to employ a closing-plunger, in connection with a riveting-plunger, and hence we do not claim the same, broadly 5 but,

Having fully described our invention, what we claim as new, an d desire to secure by Letters Patent, is-

l. In a riveting-machine, the combination, with a frame having a rigid piston, of a plunger resting on said frame and provided at one end with a cylinder, and at its opposite end with a riveting-tool.

tion of a riveting-plunger having two cylin-f ders formed therein, a rigid piston, and a movable plunger situated within one of the cylinders of the movable plunger, substantially as set forth.

et. In a machine for riveting, the combination of a plunger provided with two cylinders and a riveting-tool, a rigid piston, a movable plunger provided with a closing-tool, and a push-back plunger for forcing the cylinder and plunger back to their closed or normal position.

5. The combination of the plunger provided with a riveting-tool, and with the cylinder It', the plungerR, push-back plunger S, and cylinder T, substantially as set forth.

6. The combination of the plunger Q, provided with a riveting-tool, stationary piston I), cylinder R, and plunger R, provided with a closing-tool, substantially as set forth.

7. The combination `of the plunger Q, provided with a.riveting tool, the piston l?, the cylinder R, plunger R, provided with a closing-tool, and the push-back plunger, substantially as set forth.

S. The combination of the plunger Q, provided with a riveting-tool, the cylinder It', plunger R, provided with a closing-tool, the

vcylinder T, push-back plunger S, and pipes b and a, substantially as set forth.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

RALPH HART TVEDDELL.

Vitnesses H. G. SCOTT, XVM. BAILEY. In testimony whereof we have signed this specication in the presence of two subscrib- 

